Pregnancy toxaemia in sheep and goats has also been called ketosis, lambing/kidding sickness, pregnancy disease and twin-lamb/kid disease. It occurs in all parts of the world and is an often fatal disease occurring during the last months of pregnancy. Death occurs in two to 10 days in about 80 percent of the cases. Pregnancy toxaemia is characterized as a metabolic disorder caused by low glucose concentrations in the blood and excessive breakdown of body fat to compensate, whereby “ketones” are the toxic by-product produced during this rapid breakdown of fat. Economic losses because of the disease have been considerable, and it is the most commonly occurring metabolic disease of sheep and goats.
Inadequate nutrition during the last one-third of pregnancy is the primary cause of low blood sugar/pregnancy toxaemia, as ewes and does cannot consume enough energy to meet the demands of their growing foetus(es). This is because approximately 70 percent of foetal growth occurs during the last 4 to 6 weeks of pregnancy. Over-conditioned ewes and does are susceptible to pregnancy toxaemia because of malfunctioning of the liver. Under-conditioned ewes are also susceptible as they cannot eat enough to meet their own nutritional needs, let alone the added burden of developing foetuses. Ewes and does carrying multiple births are also at high risk for pregnancy toxaemia. Ewes with triplet foetuses require 230% more energy than ewes with single foetuses. Actually, anything that affects the ewe's or does' ability to eat enough during late gestation can result in pregnancy toxaemia: multiple foetuses, fat ewes/does, thin ewes/does, small ewes/does, timid ewes/does, granny ewes/does, dental disease, parasitism, and/or lack of exercise as described by Susan Schoenian in “Pregnancy toxaemia in ewes and does” (2002 online article).
In order to prevent pregnancy toxaemia, nutrition management of the animals is beneficial, whereby the ewes/does are provided adequate energy in their ration during the last 4 to 6 weeks of gestation. The latter is accomplished for instance by grouping the ewes/does in function of the amount of foetus(es) and providing adapted nutrition with the addition of concentrates if needed. In order to group the ewes/does in an appropriate nutrition group an ultrasound scan may be performed between days 35 and 55 of gestation. However, after the grouping a miscarriage might occur (possible as a result of the scan) or the scan might have provided incorrect information (i.e. counting the same foetus twice or counting two different foetuses as one), therefor still resulting in mal-nutrition of the ewe/does and the presence of pregnancy toxaemia.
Treatment of pregnancy toxaemia may comprise a cesarean section or induced abortion to remove the nutritional drain on the mother or by providing energy in the form of glucose or glucose precursors up to kidding of the ewe or doe, as by, for example, intravenous glucose or dextrose injections, oral administration of propionate, glycerol, propylene glycol, molasses, etc.
Therefor there is a need for novel methods and systems for monitoring and/or preventing pregnancy toxaemia.